The instant invention relates to a process and device for piecing on an open-end spinning device in which a fiber feeding device is switched on and the fiber stream produced thereby is deflected and removed on its way between the fiber feeding device and a fiber collection surface and in which a yarn is then fed back to the fiber collection surface whereupon, in synchronization with this back-feeding of the yarn, the fiber stream is again deflected and conveyed to the fiber collection surface even before the fiber stream which is started by switching on the fiber feeding device has reached its full force, and in which the yarn is again drawn off continuously while fibers are incorporated into it.
According to a known process of this type, the feeding device is first switched on to deliver fibers which are however at first prevented from reaching the fiber collection surface (DE 39 03 782 A1). In synchronization with the running-up of the fiber flow, the yarn is then fed to the fiber collection surface. When the fiber stream has reached the predetermined force below full production force, fiber removal is stopped in that the fiber stream is now fed to the fiber collection surface. The running-up of the fiber stream acting in the spinning rotor is often so rapid that sufficient time is no longer available to adapt the acceleration of yarn withdrawal to the desired extent to the running-up of the fiber stream once the fiber stream, which was first taken for removal by the fiber feeding device, has been switched over to the fiber collection surface. It has been furthermore shown that, depending on the state of the stopped fiber tuft which is exposed to the rotating opener roller, the running up of the fiber stream may be different, and this makes it difficult to determine the moment for switching over the fiber stream to begin fiber feeding to the fiber collection surface.